There is a technique for a vehicle to record a behavior data in a memory in response to detecting an abnormal vehicle behavior, so that the recorded behavior data indicates the vehicle behavior at that time and may include vehicle information and control information. The behavior data is used in ex-post analysis (see JP-A-2000-185676 corresponding to U.S. Pat. No. 7,079,927).
In this relation, the inventor of the present application has found out the following. A system may be configured as follows. When a behavior data satisfies a predetermined condition, a record control device alone determines that an abnormal behavior (a behavior of unidentified cause) has occurred. In this configuration, even if the behavior data causing the determination of the abnormal behavior comes from a vehicle abnormality and a resultant driver's abnormal operation, the behavior data is recorded in the memory as “an unexpected behavior data” although a cause of the behavior is clear. An example is as follows. A condition for the recording device to determine an abnormal behavior is that the acceleration exceeds a predetermined threshold. If a tachometer fails and indicates zero rotation speed, the driver may press down an accelerator pedal and the acceleration may exceed the predetermined threshold. In this case, although this sharp acceleration increase behavior is attributed to the failure of the tachometer, the recording device determines that this sharp acceleration increase behavior is an expected behavior of unknown cause. In general, a memory has a finite memory capacity. Thus, if a behavior data resulting from a vehicle abnormality is recorded, a capacity for storing “unexpected behavior data” is reduced. It should be noted that a behavior data to be recorded is the unexpected behavior data, and that the unexpected behavior data refers to a behavior data whose cause is difficult to be identified.